Diaphragm-screen-operating mechanism.



No. 760,891. PATENTED MAY Z4, 1994.

G. H. MARR. DIAPHRAGM SCREEN- OPERATING MEGHANISM.

k APPLIOATION FILED JAN. 14. 1904.

` No MODEL.

` THDNoams Ps'rzns cn. PHUTQMYNQ., WASHINGTON. D4 c.

UNITED* STA-.Ties

Patented May 24, 1904. f

PATENT OFFICE-.f

.DIAPHRAGM-sREEN-OPERATING. MECHANISM.

' l SPECIFICATION forming part of Letters-Patent No. 760,891, dated May 24,1904.

Application filed January 1.4;, 1904. Serial No'. 189,043, (No model.)

. .To all whom/it may concern:

Be it known that I, GEORGE IIENRXr MARR, a resident offlllaterville, in the county of Kennebec and State of Maine, have invented certain new and useful Improvements in Diaphragm-Screen-Operating Mechanism; and I do hereby declare the following to be a full, clear, Yand exactV description of the invention, such asvvill enablewothers skilled in theart to which it appertains to make and use the same.

My invention relates to zimproved dia-f phragm-screen-operatingv mechanism, thelobf -ject of: the inventionA being to operate the screen by iluid-pressure-such as air, j gas, or liquid might in some instancesbe employed; and it "consists in certain-novel features of ,constructionsan'd combinations and arrangements of parts, as will be more fully hereinafter described, and pointed out in the olaimsf- In the accompanying'drawings, Figure 1 is a view invertical section illustrating my improvements. Fig. 2 -is a view in sectionon the line J a of Fig. l. Fig. Bis aview in section on the line w ,w ofFig. l, and Fig. L isa view in section on the line m of Fig. -l.'

In ,the pulp and paper making industry all of the pulp used passes through screens which usually consist of brass plates threeeighths' inch thick, with slots about one one-hundredth` inch wide, the slots being about sixinches long and spaced about threeeighths inch apart.` A diaphragm working under the plates creates a Lvacuum on. its downstroke s and i' draws through the slots .su ch particles of pulp as aref line enough, and the return motion of the diaphragm creates a pressure under the plates,- lifting the coarse particles of pulp whichzhave through the'slots another lot of fine pulp. I

In nearly all of the diaphragm-screens now in usek the motion' of the diaphragmis ,obtained by means of a cam..secured to a revolving shaft. terial,.resting on the cam and secured to the end of a suitable connection With the diaphragm-plate imparts the necessary motion to the diaphragm. Each cam operates its diaphragmf at the rate of about seven hundred strokes per-minute, and the wear on the shoe A shoe, yof wood or other mais s0 great that it requires frequent renewals, i

Aof great annoyance.

I In vorder to overcome the above objections, my improvements were devised and will now be described in detail.

The method which I havedevi'sed is intended to displace the driving-pulley, cam-shaft', camshaft boxes, cams, cam-shoes, and cam-shoe holders of the screens as ordinarily constructed, and consists of a casting A, Fig'. 1,..

of-,proper shape and design to contain the working partsof 'the device, secured to the screen-frame B B by the bolts c and dowelpins a and provided with a cap ft2, held in position by studs t3 and nuts at. Cap t2 holds in vposition a bronze bushing In', which serves as-a guide for the diaphragm-rod 9', which passes through it. To one end of the diaphragm-rod is secured by set-screw c the holder C, into which is threaded the piston D, fitted with grooves d and OZ. Radial holes d2communicate with the :chamber 033, and radial holes dt communicate with the chamber 0X5. Holes d allowthe use of a Spanner-wrench for screwing or unscreW- ing piston D from the holder C, and the hexagonal recess Z7 in piston D allows the use of f a hexagonal wrench for the sam epu rp ose after removing the screwed plugI. Circumferential groovesd8 on piston D serve to pack same j and-to hold lubricants. lodged over the slots, thusfreeing them so that .f the vacuum-stroke of the diaphragm will takel 4 `and is heldin placeby the'gland H and the vscrewed plugI. The shellGisfurnished with A bronze-or steel cylindrical shell G fitted into the casting A, .surroundsthe piston D,

internal grooves g and g and external grooves g2 and g3, connected by radial holes g4 and g5, the purpose of which willbe described later. The glandH is adjustably -secured to casting A by studs t and nuts /t tzand -is'provided with a lubricating-recess h3. .Y

' A cover or hood K serves to protectk the gland H and its adjusting-studs /t and is secured to holder C by set-screws K.

TOO

ln Fig. 1 is shown such portions of ascreen as ordinarily constructed as is necessary to eXplain the working of the device. L is the screen-plate, provided with slots Z and secured by screws Z to the framework M, which is secured to the sides N of the screen-body.

Between the sides N and the framework O of the screen-body and secured to the four edges of the wooden diaphragm-plate P is the rubber diaphragm Q. To the under side of diaphragm-plate P is the cast-iron plate R, secured to P by bolts 9 and to diaphragm-rod r by set-screw r2.

To the under side of screen-body O is bolted a cast-iron bridge-tree S, provided with a cap s, secured by bolts s and holding in place a bronze bushing s2, serving as a guide for diaphragm-rod r', through which it passes.

kThreaded on diaphragm-rod 0 are the two nuts r3 r4.

Encircling the diaphragm-rod 9 and pressing against the nut r3 and the bridge-tree S is the helical spring T.

The device operates as follows: The diaphragm-rod r' being in its lowestposition and unscreened pulp in the space above screenplate L, compressed air or the operating medium enters groove g3 through the hole a5, Fig. 4, and passing through radial holes g5, groove g', groove d, and radial holes d* enters the chamber d5 and acting on the piston D raises same until the top edge of groove d reaches the lower edge of groove g and the air is free to pass into the atmosphere through chambers Z7 d3, radial holes d2, grooves d g, radial holes g4, groove g2, and radial holes a, (Shown on Fig. l and Fig. 3.) This is the upstroke of the diaphragm,which clears the slots Z in the screen-plate L of coarse particles of pulp, as previously described. The lower edge of groove d having reached the top edge of groove g', as shown in Fig. l, the supply of compressed air is cut off, so that the under side of piston D is subject to atmospheric pressure only, and the pressure of the spring T, acting between the nut r3 and bridge-tree S, in addition to the weight of the diaphragm and its moving parts and the weight of the water and pulp above the diaphragm, returns the piston D to its first position and completes the downstroke of the diaphragm, producing the vacuum-stroke, as already described, d rawing the fine particles of pulp through the slot Zin screen-plate L, which particles pass out of the screen through openings. (Not shown on the drawings.)

The number of strokes of diaphragm is governed by the valve which admits air at a5.

While best results are obtained by allowing the diaphragm to return by gravity, it can be returned by the air-pressure, if desired, by arranging the air-passages in piston D and shell j G with that object in view.

The air-cushion formed when the piston D is returning to its lowest position eliminates the jar produced by the cam-shoes and cams as usually constructed.

The screwed plug I and the adjustable gland `in the relative arrangement of parts shown and -described without departing from the spirit and scope of my invention. Hence 1 would have it understood that I do not wish to coniine myself to the exact construction of parts herein shown and described; but,

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The combination of a screen-plate diaphragm, aiuid-pressuremotor and means connecting said motor directly with the screenplate diaphragm.

2. The combination with a screen-plate diaphragm, of a piston connected directly therewith, and fluid-pressure mechanism for controlling said piston to operate the diaphragm.

3. The combination with a screen-plate diaphragm, and apiston connected directly therewith, of a casing around said piston adapted to direct fluid beneath the piston to lift the diaphragm and a spring to assist the weight ofthe parts, to lower the diaphragm.

4. The combination with a screen-plate diaphragm, of a piston connected directly therewith, a spring normally forcing said piston in one direction, and fluid-pressu rc mechanism for controlling the movement of said piston in the other direction.

5. The combination with a screen-plate diaphragm, of a rod connected directly therewith, a spring on said rod normally pressing the same downward, a piston on the lower end of said rod, a casing around said piston, and grooves and ducts in said casing and piston to admit a fluid below the piston to raise the same and permit the escape of said fluid when the piston reaches the desired height.

6. The combination with a screen-plate diaphragm, of a rod connected directly therewith, a spring on said rod pressing the same downward, a piston on the lower end of said rod, a casing around the piston, and inlet and outlet grooves and ducts in the piston and casing to direct the passage of a iiuid to raise the piston and escape from beneath thc same when the piston reaches a predetermined height, to permit the spring and weight of parts to lower the piston, rod and diaphragm.

7. The combination with a screen-plate dia- TOO lIO

phragm, of a rod connected directly with said diaphragm and'l extending downward therefrom, a frame, a casing secured in the frame, a hollow piston in said casing, a removable 5 plug in the frame below the piston closing the lower end of the casing, and said casing, frame, and piston having grooves and ducts therein to direct the passage of a'luid into and below the piston to elevate the same and permit the predetermined height.

In testimony whereof I have signed-this specification in the presence of two subscribing witnesses.

GEORGE HENRY MARR.

Witnesses:

JAMES L; DEAN, PERCY M. CRAM.

escape of said uid when the piston reachesa lI0 

